Frequently in the telecommunications industry, it is desirable to splice together two or more cables, either to extend a cable or to tap into another cable. The formation of a splice involves removal of the outerjacket and other layers of the cable to expose the individual conductors or optical fibers which are then individually connected to the conductors or fibers of another cable or cables. After the splice is formed, it must be protected from water and other vapors to prevent corrosion or a short circuit. For this purpose, the splice area is often enclosed in a splice case that is formed from two trough-like half shells with separate end plates or seals. Different end seals are used to accommodate different diameter cables and splice cases of different dimensions.
An example of such an end seal is disclosed in U.S. Pat. No. 5,258,578 (Smith et al.). This end seal is adapted to seal the space between the cables and the splice case to restrict fluid transfer through the seal. The seal is formed from a body of an elastic, flexible material such as a gel having self-adhesive properties. The body comprises a core portion and a tail portion. The core portion has a shape corresponding to the ends of the splice case and includes cylindrical openings through which the cables extend. The opening are exposed at the outer peripheral surface of the core. The body of the seal also includes a tail portion that is integral with, and extends from, the sur face of the core portion. The tail portion has a length sufficient to wrap about the outer peripheral surface of the core to cover all the cylindrical openings. The openings are generally smaller than the diameter of the cables to be placed therein so that the elastic core must expand for the openings to accommodate the cables. When wrapped around the core, the tail seals the portion of the cable between the core and the inside surface of the ends of the splice case.
As a result of its elastic properties, the previously described end seal is capable of sealing a variety of different diameter cables. The diameter of the end seal is determined by the number of cables extending through the core, the diameter of the cables, and the length of the tail portion. As a consequence, the diameter of the end seal is easily changed. This feature allows the end seal to be used in splice cases of differing diameter.
One limitation of this end seal is that, whenever it is removed from a splice case, the seals formed between the core and the cables extending through the openings in the core are disturbed, and therefore the cables must be repositioned upon re-installation of the end seal. Moreover, while the diameter of the end seal can be varied, this feature is unnecessarily cumbersome in those situations where splice cases of a standard size are to be used. In particular, because the end seal is not standardized for any given splice case, additional hardware, such as gaskets or washers, are sometimes required to properly insert the end seal in the closure. In some cases, it is even necessary to trim the end seal so that it will fit in the closure.
There is thus a need in the art for an end seal assembly in which the cables remain fixed in the core even when the assembly is removed from the closure, and which can be made compatible with many different cables and closures with a minimum of effort.
A further problem encountered with some existing end seal assemblies, particularly those which are wrappable (e.g., end seals of the core-and-tail variety) or which have a layered configuration, has to do with telescoping. With a core-and-tail type end seal, for example, the tail portion is often wrapped somewhat loosely around the inserted cable at the time it is placed into the assembly. As a result, a sealant or adhesive which is injected into the end seal has a tendency to ooze through any gaps between overlapping sections of the end seal. Moreover, if a longitudinal force is applied to the inserted cable before the sealant or adhesive has hardened sufficiently, the end seal will tend to telescope inwardly or outwardly from the closure, thereby undermining the integrity and mechanical strength of the seal. There is thus a need in the art for a wrappable end seal which resists telescoping and which minimizes loss of sealant or adhesive through gaps in the end seal.
These and other needs are met by the present invention, as hereinafter described.